Arson investigators outside the smoldering home where a gunman shot dead a father and his 4-year-old son, then set their duplex ablaze near Los Angeles.AP

INGLEWOOD, Calif. — Police searched for a gunman who wore a painter’s mask as he set fire to a home before going on a shooting spree early Saturday, killing a father and his 4-year-old son and injuring a woman and two other young children near Los Angeles.

The 30-year-old father was shielding two of his children when he was shot, Inglewood Police Chief Mark Fronterotta said.

Also, the 28-year-old woman — said to be the children’s mother — carried the wounded 4-year-old to a neighbor’s yard after the attack.

“This extraordinary rescue attempt by the mother occurred in spite of the fact that she had gunshot wounds to both legs,” a police department statement said.

A SWAT team has set up a perimeter and was using dogs to search for the attacker, who may have lived in a rear house on the property, Fronterotta said.

Police have no motive. But a neighbor, Judy Castellanos, told the Los Angeles Times that the suspect lived in one of three units on the property and described him as “really weird” and “dangerous.” She said he had not paid his rent for years and that a new property owner had been trying to evict him.

“He had been asked to leave by the end of this month,” she told the newspaper, adding that he was reclusive and would not let anyone look inside his home.

Five neighboring houses in Inglewood were evacuated as officers searched residences and the trunks of cars. Other nearby residents were told to remain inside with their doors locked. The suspect was described as armed and dangerous.

Detectives determined the suspect set the house ablaze at about 4 a.m. before he began shooting, Fronterotta said.

He apparently wore a painter’s mask during the attack to try to shield his identity, the chief said. Investigators were trying to determine whether he fled or remained in the house as it burned.

Television footage showed a home gutted by flames and a plume of smoke rising over the residential neighborhood early Saturday.

The woman was being treated for gunshot wounds and was in critical condition, as was a 6-year-old boy with a gunshot wound to the pelvis and a 7-year-old girl with a gunshot wound to the chest, according to a department statement.